The invention described herein relates to a device for bonding two different materials. Applications include chip card manufacturing and, more precisely, the manufacture of the chip base such chip cards contain.
Chip card use is on the increase, notably in the digital payment field with bank and phone cards.
It is common knowledge that a chip card consists of a stiff plastic card with a hole, generally located in one of its corners. The hole receives an assembly of a base and an electronic component, commonly called a "chip". The chip base itself is usually made of two component parts, viz. a perforated metal part called a grid and an insulating part. The grid acts as a connecting interface with the chip. The grid is divided in separate areas or connectors, each designed to enter into contact with a pin of the machine the card is inserted in. The opposite side of the grid is covered with an insulating film with a certain number of perforations. Each perforation is precisely positioned on an area of the grid. It is thus possible to connect each grid connector with an area of the chip using metal but usually gold wire.
To automate the manufacturing process, highly precise positioning is required to match the perforations in the insulating layer to the metal grid.
As a rule, grids are produced on long strips onto which the insulating layer, a strip of equivalent width, is hot-bonded. Unfortunately, as materials differ, grid and perforation intervals are not rigorously the same. This precludes the manufacture of very long strips, unless patterns are realigned.
The problem quite clearly stands in the way of automatically producing very long strips.
In an attempt to solve the problem, a complex machine has been proposed that operates on the following principle. On a uniform length of metal strip on which grids are located at given intervals, an insulating strip with perforations located at slightly narrower intervals is placed. The insulating film is stretched over the uniform length of metal strip in such a manner as to match the perforations in the insulating strip with those constituting the grids. Stretch is controlled by a match-detecting camera system. When perfectly positioned, the insulating layer is applied and bonded to the metal strip. Though producing satisfactory results, the device, operating in a sequential manner, is not suited for mass production.
This state of the art may be illustrated by the contents of patents GB-A-2 031 796 and WO-A-92 15118.
To solve the problem of matching the insulating strip perforations to those in the metal strip, a solution has been proposed in conformance with patent EP-A-0 296 511. The patent describes a device in which perforated sheets of insulating material are placed on and bonded to a metal strip in a manner that matches the perforations in the insulating material to those in the metal strip. According to the device disclosed in the patent, each sheet is placed on and subsequently bonded to the metal strip with no micro-alignment between the positioning and bonding operations.
The problem the invention aims to solve, therefore, is that of making a bonding device that will attach a metal strip with periodic perforations to a strip of insulating material with perforations spaced at like intervals. To solve the problem, a device has been conceived and developed comprising:
a system to perforate the insulating strip at regular intervals on the one hand and cut said insulating strip in sections, on the other; PA1 a system to position the metal strip onto said sections of insulating strip and a system to convey the metal strip positioned onto said sections of insulating strip; PA1 a system to micro-align each section relative to the metal strip onto which the section has been placed to match the perforations of each strip with great precision; PA1 a system for bonding each section of insulating strip to the metal strip. PA1 a system for precutting the sections; PA1 a system for affixing at least one length of adhesive tape as a function of strip length at least onto the precut areas; PA1 a system for severing the areas not precut to obtain separate sections, temporarily linked by at least one length of adhesive tape. PA1 a main platform designed to carry cutout sections acting as the top of each link; PA1 a plate within the link body, set back from the platform and movable parallel with the length of the strip and equipped with feed studs, said studs protruding through the holes of a greater diameter in the platform. PA1 a chain of press plates moved along at the same speed as the conveying chain, each of the press plates having the same dimensions as the platforms it faces and touches; PA1 two sets of inductors facing each other, the lower set being located slightly below the trajectory of the conveyor platforms and the upper set being located slightly above the trajectory of the press plates, in such a manner that energizing the inductors will set up a current across the facing metal plate.
Given this combination of systems, it is clear that the device simultaneously moves the metal strip and positions each section relative to said strip to rigorously match the perforations. As centring and conveying operations are concomitant, bonding is a continuous process requiring neither stopping nor adjustment sequence.